Fuel injection system



Dec. 1, 1959 J. F. ARMsTRoNG 2,915,053

FUEL INJECTION SYSTEM Filed May 24, 1957 2 sheets-sneer 1 Dec. 1, 1959 AJ. F. ARMSTRONG FUEL INJECTION SYSTEM Filed May 24, 1957 INVENTOR. JAMESFRED ARMSTRONG 2 Sheets-Sheet 2 BZW/mw ATTORNEY 2,915,053 v V- FUELnsuEcTloN SYSTEM James Ff Armstrong,` St.-Louis, Mo., assigner toACFIndustries, Incorporated, New York, N.Y., a corporation of New JerseyApplication May `24, 1957, serial No. 661,331'A 1s claims. (ci. 12s-119)This invention is an engine fuel charging device operat-v ing as acontinuous flow system and adapted for intake `port injection, in whichsystem the fuel is pressurized, measured under pressure in accordancewith engine requirements, and distributed under pressure to pointsVadjacent the intake valves of the several cylinders or combustionchambers of the engine. A

This application shows an improvement applicable to the basic systemshown in the prior patent to James Fred Armstrong, No. 2,785,669, datedMarch 19, 1957, and entitled Injection Carburetion. A more completeunderstanding of the invention herein disclosed will be'had by referenceto other prior applications of James Fred Armstrong, Serial No. 632,798filed January 7, 1957, for

l Fuel Injection System, and Serial No. 646,063,1iled yMarch 14, 1957,for Fuel Injection System.

The improvement herein disclosed may be applied to any of these priorinventions, as well as others which function on similar principles. t

This description will be limited to an explanation of modifications inthe basic systems above referred to.v For example, in the Armstrongapplication Serial No. 632,798 .tiled January 7, 1957, for FuelInjectionSystems, is described a means'for stabilizing the datumpressurev by. a by-pass device for bleeding the datum line rapidly offuel in response to a pressure increase in the rdatum system withrespect to the pressure in the charging system. It

2,915,053 Ptrtentec'lDec.` 1,

ice

2 According to this invention, the capacity of the datum system ischanged by throttle movement either through a portionof or throughoutthe total range of movement thereof. l

The accompanying drawings are illustrative'ot" asystem withmodifications which will carry Vout. all ofthe i objects of theinvention.

In the drawings:

Fig. 1 is a schematic representation showing the interconnection vof theelements of the system.

Fig. 2 isan operational view of some of the ,elements shown in Fig. 1.

Fig.` 3 is a schematic representation of a modified form of regulatorillustrated in Fig. l.

l In the detailed description of the invention which fol lows, the samereference characters will be used, where possible, to indicate theelements ink this system `corresponding with those in my prioridentified applications and patent.

Engine charging fue! system In Fig. l the fuel supply line 19 from thefuel tank connects with the inlet of the pump P. The outlet of the plumpP connects by way of line 20 through a check lvalve with'the pressureregulator 22. yWthinthe pressure regulatoris a diaphragm 22o acteduponbythe pressure of the fuel passing the valve 22h controlled by thekdiaphragmQThe spring 22d acts upon the rear face of the diaphragm 22oina direction'toopen `the valve 2'2b.

operated within metering oriices23 by a crosshead dewas recognized that,in the basic patented system, an increase in fuel ow through the nozzlesresultedv in a movement of the nozzle diaphragms to open the nozzlevalves, and that this diaphragm movement in response to increases inmetered fuel flow caused a slight increase in pressure in the datumsystem exceeding normal regulated pressure which retarded valveresponse. In other words, there was a lag in nozzle valve operationwhich occurred as a result of increases in the metered flow of fuel'tothe nozzles. ,One solutionV to this problem was to bleed off through 'aby-pass sufficient fuel to maintain the datum pressure constant. Anothersolution is to accommodate the fuel displaced into the datum system bymovement of the nozzle diaphragms by temporarily enlarging the capacityof the datum system.

According to this invention, the datum system is provided with avariable capacity chamber, the volume of which is increased inanticipation of engine operating eventsV which will result in a need forrapidincrease in vice 34. The position `of the rods 33 is, in turn,Vcontrolled by a magnetic clutch 3S from a shaft36n operated by an airvalve in the air induction. system of the engine hereinafter described.,y j t `Each metering orifice 23 is connected by a separate line I24with a fuel nozzle 25. Thereare usually as many fuelnozzles asthere arecylinders ofthe engine, but only four have been shown here. j

Each `nozzle 25 has a stern portion 25a which 'may be xed within thecylinder v,head ory induction manifold for thev engine, so vas todischarge y`fueljadjacent an 'intake valve` of an individual cylinder ofthe engineV (nots'liown). Within the stem 25a' is a-'valve'elem'ent-29controlling the outlet port of thenozzle, and this valve element `29datum pressure control line is connected.

the-opposite side of the diaphragm '.28 to which `the The datum pressuresystem The datum pressure system connects ,with each' of the chambers 57of the nozzles 25, andthe fuel pressure Y therein is established by theaction of two pressure reg-` j ulators controlling the inlet .andthe`outlet therefrom,

of the mixture V.simultaneous with or preceding and `anticipatingreduction in `fuel flow to the engine.

and, incidentally, `the-pressure drop across a discharge restrictionfrom the datum pressure system t o the inlet of the pump P. Fuelpressure is supplied to the ldatum system from the chamber A by-way ofaline 56` to pressure regulatorC.` `This regulatorcomprises a casingcontainingra diaphragmjl dividing the casingintcrA a pair of chambers`72and 73. A spring 74 acts in a direction on the diaphragm 71 tending toclose the valve 75 which is operated from the diaphragm. Referring backto my prior applications, the valve 75 forms a variablerestriction forcharging the 4datum system and corresponds inl function to metering rod87. Datum pressure line '58 is supplied with fuel under pressurefromline56'iwhe'n valve 75 is open, and has a connection 59 with chamber 73of the pressure regulator C. LineSS extendsfto the datum pressurechamber ofeach of the nozzles' 25 by way of the series of branches 58a,58k, 58e and 58d. At the outlet of' the'daturn pressure line 58His ametering restriction 61 in the'form of a centrifugal jet or orifice;

Downstream of the orifice 61 is .the pressure regulator 60'which hasachamber 164 therein` formed by a diaphragm 165. A passage 163 connectschamber 164 with the metering restriction 61. Diaphragm 165 has aplunger 168 operating against a lever 169 which, inturn, controls thedegree of opening of valve167. Spring 166 resists the pressure of fuelin the chamber'164 on the diaphragm 165. 1

The lower portion of the casing of pressure regulator 60 has a pivotedlever 172 forced upwardly by the compression spring-.180,` which'appliesa force by way of the pivot 170 to the lever 169.

Air induction system for the engine TheVV engine (not shown) is providedwithan air induction system having an air horn B communicating with a`plurality ofbranches which leadv to the separate combustion chambers ofthe engine. These separate branches a're not'shown because the parts ofthe air induction 'system are' conventional.

Air fow metering The air metering orfmeasuring part of this system,indicated as B 'in Fig. l, may be placed, anywhere near the engine andconnectedwith the inlet of the engine intake manifold,fwhich has severalbranches (not shown) leading to the'separate intake ports ofthe engine.This air measuring or metering part, termed the airhorn, has a tubular'body constructed ,for connection at its lower or outlet end to theintake manifold of the engine. The-outlet of the air horn is controlledby a suitable throttle 50 mounted on a throttle shaft 51, andcontrolledv by a throttle arm 52 actuated by a linkage R from thethrottle pedal T.

Above the throttle is a balanced air valve 37 mounted on' a suitableshaft 36 journaled in the walls of the air horn B. On the lower leadingedge of the air valve 37 is a deflector 37a which produces anaerodynamic unbalance tending to close the valve at openings above 55.The valve 37 is moved in the opening direction by a servomotor which hasa diaphragm 40 operating against a calibrated spring 43 and a connection`39 with the air valve 37. The servo-motor'is powered by the pressuredrop across the air valve 37 as sensed by two Pitot tubes44 and 45upstream and downstream of the air valve 37, respectively. A slottedbaffle 49 extends between the air valve shaft 36 and the throttle shaft51 in a manner to eliminate aerodynamic interference of the flow aroundthe throttle 50 with displacements of the air valve 37.

A by-pass 79 extends around the edge of the throttle 50 when in theclosed position, and has a needle valve 77 for adjusting the lay-passedair to control the idle speed of the engine. n

Alby-pass 80 extends around the edg'eof the air valve and has a meteringscrew 78 for adjusting the amount of air by-passing the airvalve 37`inthe idle range of displacements of this valve so Vas to adjust themixture ratio at'idle.

The air valve 37 is displaced by the power operated servo-motor so thatit takes-up an angular position in` dic'ating` the rate of air ow pastthe throttle-50 to the engine. Shaft 36, upon which it is mounted, is inturn connected to the fuelmetering part A by means of a magnetic clutch35 to control the displacement of a plurality of tapered fuel meteringrods which are calibrated to flow fuel at a rate to give the fullthrottle power mixture throughout the range of angular displacement ofthe air measuring valve 37.

To get a part throttle economy mixture, the response of airvalve 37 toair flow is modified to produce a decrease in angular displacement ofthe air valve 37 for the same rate of air flow as at full throttle. Themetering rod displacement likewise is affected, and the rate of fueldelivery is reduced to give an economy mixture for road load operationof the engine.

Part throttle mixture Air valve response is modified for the abovepurpose by an air bleed connection 205 in the air horn B lwhich connectsthe plurality of ports 202 and 203 above the air valve 37 to the suctionside 42 of the servo-motor. In this connection is a diaphragm operatedvalve-212 which is held open against the closing force of the spring 211by suction connection 209 extending posterior of the throttle valve 50.When the throttle is open far enough so that manifold depression is lessthan six inches Hg, for example, valve 212 is closed by the spring 211against the force of suction acting on the diaphragm 208, thus 'cuttingoil the air bleed 205 from communication with-the suction side 42 of theservo-motor. The response of the air valve 37 is thus changed toincrease its opening and the displacement of the fuel metering rods toincrease the fuel delivery rate to a full rich mixture.

If, on the otherv hand, engine speed increases in the part throttlerange of engine operation, angular air valve displacement is decreasedfor the same rate of air flow, giving a lesser displacement to themetering rods 33 -so as'to lean out the mixture for part throttleoperation. As engine speed increases, however, angular air valvedisplacements will also increase as a result of increasing air ow,sothat the edge of the air valve 37 and deflector 37a swings over theports 202 and 203. This places the ports202 and 203 in a zone ofdecreasing air pressure due to high` velocity flow to reduce theeffectiveness of the air bleed on the action of the servo-motor. Airvalve response is accordingly modified to increase air valve openingand, consequently, the rate of fuel flow to the engine, giving a richermixture at higher engine speeds to eliminate-the possibility of partthrottle detonation.

Starting mixture enrichment At low engine temperatures, fuel flow shouldbe increased for starting and engine warm-up. This result isaccomplished in the instant device by modification of the response ofthe air valve 37 instead of by direct connection with the fuel meteringrods 33 which is, of course, possible. As illustrated schematicallyherein, the air horn B moun-ts a thermostatic spring 102 concentric withrespect to one end of the air valve shaft 36. One end of the spring 102is held fast in a slot in a pivoted lever 101, which in turn isangularly movable by a suction operated piston 105 in a cylinder 106vagainst the force of a calibrated spring 107. Suction is communicatedto the cylinder '106 through a line 108 communicating with the manifolddownstream of the throttle 50. The free end of the thermostat 102,indicated as'103, abuts a lever 100 fast on one end of the shaft 36,and, as the engine cools, the thermostat 102 winds up, exerting a forcein a clockwise direction on the lever to urge the valve 37 toward anopen position. The force of the thermostat depends upon the temperature,but at temperatures below those encountered in normal operation of theengine this force either actually opens the air valve 37 or decreasesthe force necessary to open the valve, so that the servo-motor producesa greater degree of valve opening and metering rod movement forincreasing the fuel ow to the engine during cranking. As soon as theengine starts, suction rotates the arm -101 to decrease this openingforce exerted by the thermostat spring 102 on the arm .100. Less airvalve and metering valve displacements will occur for'the same rate ofair flow, sol that the mixture is leaned out after the engine starts. Asengine temperature increases, so does the temperature of the thermostat102, thus decreasing the force exerted by the spring 102 on the arm 100until, at normal engine operating temperature, end 103 backs away fromthe arm 100 entirely.l

Fast idle control Engine priming circuit In this system, the mixtureratio furnished vmay not only be affected by Ymodifying the response ofthe air valve, asgabove described, but also by varying the pressure dropacross the metering restrictions 23, and since this pressure drop orpressure differential is controlled directly by datum pressure, themixture ratio can be varied one way or the other, rich to lean, bychanges in the datum pressure regulation. Because of this in` herentcharacteristic of the system, it is possible to add to it the manydesirable auxiliary features necessary to adapt the system to the needsof the engine.

For example, the particular engine might require a richer mixture duringcranking in order to facilitate engine starting. This function can bebuilt into the present system by a control which acts upon datumpressure. The following detailed description is explanatory.

The usual starter and ignition circuit for the engine includestherbattery 194 connected at one terminal to ground, and at the otherterminal to the ignition key switch 197, which switch, when closed,energizes a circuit to the starter switch S, which is connected, inturn, by a lead 198 with the starter motor 195. Connected with the lead198 is a second lead 189 extending to the winding on solenoid 173 in.the pressure regulator 60 and to ground through the lead 182i.`

vOperation of printing circuit To crank the engine, both the ignition`switch, 197 and the starter switch S are closed, so'as to complete thecircuit to the engine starter motor 195. This circuit, in turn,energizes the circuit through the solenoid 173 by way of the leads 189and 188, energizing the- `through the datum system 58. This brings intooperation the effect of the metering restriction 58H to restrict -thefuel ow in the datum system upstream ofthe metering restriction 61. Theincrease in flow through the datum .system creates a-pressure dropbetween the restriction 58H and the metering restriction 61, vthuslowering the datum pressure acting on veach of the nozzle diaphragms ofthe nozzles 25. When the datum pressure is lowered,

the pressure downstream of the metering restrictions `23v is likewiselowered, increasing the pressure drop and-the fuel 'ow past the meteringrods 33 to the nozzles at any particular position of the rods 33. Thispriming function is accomplished only when both the ignition switch andthe starter switch are closed. i 1,

Ignition switch fuel cut-ofi circuit In this system, the datum circuitforms a remote control for the discharge from the nozzles. When` thepressures between the charging system and datum system are equalized,the fuel discharge from ,the nozzles -is effectively cut off. One mannercontemplated forutilizing this inherent feature is illustrated in Fig.l.

`In this particular embodiment, datum line 58 is` directly connectedwith the fuel chamber A by a pressure equalizing line 300. Communicationthrough the line 300 is in turn controlled by a solenoid operated valveSV, which is spring-biased to an open position and closed byenergization from either of two electric circuits connected withseparate windings inthe solenoid valve SV.

The lrst of these circuits comprises a line 299 connected with theignition switch 197 and extending to one of the solenoid windings of theswitch SV. The lead 298 connects the same winding to the opposite sideof the starter switch S. In this circuit is a vacuum operated switch VS,which is held closed by spring pressure from the spring 250 under normalengine operating conditions.

Operation of ignition switch controlled fuel cut-ofi In the followingdiscussion of the operation of the above-described circuit, the functionof the vacuum op erated switch VS will be ignored.

'The ignition switch 197 controls the energization of `the lead 299,which in turn, when closed, furnishes the necessary` current to oneofthe windings in the solenoid valve SV to vclose the valve against theresistance of the spring 303,'whicl1 tends to maintain the valve open.If the starter switch is open, as would be the case when the engine isrunning, then this circuit is grounded throughv the starter motor 195 byway of the leads 298 and 198. With the ignition switch 197 closed,therefore, solenoid operated valve SV is energized and closed by the'`circuit grounding through the starter motor, as described, and thepressure equalizing passage 300 is inoperative. It will be understoodthat the current flowing through this circuit is necessarily very small,due to the resistance of the solenoid winding, so that it has no effectupon the operation of the startermotor 195. It requires a much greateramperage to operate the starter motor 195 than it does to operate thesmall solenoid operated valve SV.

When the ignition` switch 197 is open, however, the circuit through theleads 299 and 298 isde-energized,

allowing spring 303 to open the solenoid operated valve SV. `Thisequalizes the pressure between the fuel charnber A and the datum line58, so that each of the valves in the fuel nozzles 2S closes anddischarge of fuel immediately ceases.

Conversely, when the ignition switch 197 is turned on,

valve SV closes.

Operation of deceleration fuel cut-crc In the circuit above described isa switch VS operated in response to a negative load on the engine foropening the circuit 299-298. Preferably, the switch- VS has a diaphragm251 connected through a rod 252 to the switch. The diaphgram 251 issubject to atmospheric pressure on one side, tending to open the switch,and to manifold `pressure on its opposite side through `theline 108. A

spring 250 may be calibrated so that the switch 253 remains closed untilmanifold suction exceeds the normal range of variationsv encountered inoperating the engine under its own power. In other words, switch 253`re- `mains closed until manifold suction exceeds 21 or 22 kdischargefrom the nozzles 25 is effectivelyfcutoff.

7 Unloading' -If,.f'o'r anyreason, the starting mixture is to'o rich sothattheengine-willnot re during cranking, it is necessary to provide forsome means to unload the engine of fuel. Under thesecircumstances,continued delivery of fuel from the fuel nozzles 25 isnotv desirable. Here, again, datum pressure regulation forms aconvenient manner for remote control of the discharge from the fuelnozzles 25.

When the ignition switch 197 and starter switch S are closed, thecircuit 299 and 298 is short-circuited, so that it becomes inoperativeand the current ows directly from the switchS to thestarter motor 19Sthrough the line 198.

Theunloading circuit connects with the line 198, which is energizedunder these conditions, through lines 298 and'304 to theswitch TS, andfrom thence through the line 301 through a second winding on thesolenoid valve SV to ground. Thus, normally, the valve SV is vmaintainedclosed, even though the circuit 298-299 is inoperative.

Operaton of lmloader With both ignition switch 197 and starter switch Sclosed, the engine is cranked due to the energization of the startermotor 195. As above explained, circuit 183 and 189 is also energized atthis time to effect priming by lowering the datum pressure in the line58. The circuit 198, 298, 304 and 301 through the second winding on thesolenoid valve SV is likewise energized, maintaining the pressureequalizing passage closed, so that the priming` system remains inoperation until the throttle is opened wide. This movement of thethrottle engages the lug 152 on the throttle arm 52 with the throttleoperated switch TS, which opens the circuit between line 304, which isenergized, and line 301, which extends to the winding on the valve SV.Spring 303 then opens pressure equalizing passage 300, and the pressurein the charging' and datum circuits becomes equalized, closing the.nozzle valves 25 to shut oft the discharge of fuel to the engine.

As above explained, the starter switch S short-circuits the electriccircuit through the lines 298 and 299, so that there is no closing forceexerted against the spring 303, and the valve remains open while thethrottle is held wide open and the starter switch remains closed.

`Fuel mixture control regulation for acceleration In order to obtainsolid throttle response in most engines, it is necessary to increase thefuel-air ratio fed to the engine simultaneously with throttleopening, orat least prevent theoccurrence of a lean mixture condition. In otherwords, the pressure carburetor or injection system shouldperform thefunction of maintaining or enriching the fuel-air ratio simultaneouslywith throttle opening to accomplish the result performedin thecarburetor by the accelerating pump. One way of accomplishing thisparticular result is disclosed in my prior applications, whereinmanifold suction changes are used to trigger theresponse of the airvalve 37 and cause it to over-travel in an opening direction. This airvalve opening increases the metering area of the jets 23, and thereforethe ow through the lines 24 and, of course, from vthe nozzle valves 25.However, when fuel ow increases through the jets 23 in the lines 24,fuel is displaced into the datumsystem by movement of theA diaphragms 28a's the nozzle valves '25 open. Operation of the diaphragms 28 inresponse to opening movement of the needles cannot yoccur until the fuelldisplaced is discharged through-the metering restriction 61. yThiscannot occur instantly. Consequently, this restrictionis responsible forcertain lag in performance from the time that the needles are moved'vopen to the time the fuel is delivered to the engine.

In prior devices, a separate by-pass bleed wasprovided from the datumsystem to a point downstream ofthe ybetween the two levers 311 and 314.

metering restriction. y61 to accommodate the fuel displaced bythediaphragms 28. y

In this system, throttle movement creates an increase in capacity of thedatum system a't a rate equal to or greater than the rateiof decrease incapacity caused by movement of the-diaphragms 28.

Connectedwith the-datum line 58 by the line 130 is an expansible chamber126 provided with a exible wall 127. Contactingv the flexible wall 127are a plunger 128 and a spring 129. A link 310 connects plunger 128 witha pivoted lever 31'1 operated from the throttle shaft 51 by a. link 312interconnecting levers 313 and 314. The pivot 305 forms a common hingepoint for both the levers 311 and 314. Between the levers is acompression spring 306, and an adjustable clamping screw and nut 307 isprovided adjacent the spring to limit the distance A fixed abutment 308carries a screw 309 positioned to contact with the lever 311 and limitits travel in response to throttle opening.

Operation of fuel mixture control regulation for acceleration Fig. 2 isan operational view illustrating the approximate relation between theparts during full throttle acceleration from-low speed. Full throttleoperation of therenginecauses'valve 212 to close,.cutting oir the partthrottle bleed through the lines 205 and 209. This will cause the airvalve 37 to assume a position displaced a substantial amount from idleposition (from about l0 or 12 degrees to 30 degrees or more) so as towithdraw the needles 33 and increase the fuel ow through each of theVlines 24 tothe nozzles 25.

yOperation of the throttle 51 to the wide open position rotates levers313 and moves link 312 and lever 314 into the position shown in Fig. 2.When lever 314 is moved in this manner, spring 305 lifts lever 311around pivot 305 until contact is made between the lever 311 and thestop 309. This movement withdraws plunger 128 and allows the movablewall 127 to compress spring 129an amount which is adjustable by the stop309. The capacity. of the datum system is increased by creating a flowinto the chamber 126 at a rate equal to or greater than thel rate ofdecrease in displacement caused by movement of the diaphragms 28. Therate depends upcn the calibration of spring l129. The response of theregulator C is limited by restrictionSSH in the line 59. This permitsthe change in capacity produced by the movable wall 127 to maintainthedatum pressure constant or decrease the datum pressure, whichever isdesirable, with increases in the rate of flow to the nozzles 25 due to`increase in air ow to the engine.

The adjustable stop 309 normally limits the action of.

vthediaphragmto an initial range of throttle openings which correspondapproximately with operation of the Vengine in the part/throttle rangeof mixture ratios.

When the throttle is closed, the reverseaction will take place.Datumpressure will remain constant o1' will be temporarily increaseddueto decrease in the capacity of the chamber 126 as the throttle closes,maintaining con stant or decreasing the pressure drop across themetering restrictions 23, and consequently the rate of fuel flowfrom'the nozzles 25.

Fig-3y illustrates a portion of the same systemas illustrated in Fig.'ll.. In this partial schematic view of 4the system. is illustrated -amodied form of` the pressure regulator C indicated as C'. f

The regulator C has a casing '70 containing a chamber 72' supplied withfuel from the chamber A by way of a line 56' containing a restriction58H'. Correspondingpartsin this pressure regulator are indicated bythesarne reference characters with-a prime. Within the casing 70is ailexible` diaphragm 71 operating a valve 75' on-a tapered seat withinthe chamber 72.

ber 73' containing a cylindricalV guide 76' for the valve 75.Surrounding the guide 76 is a spring 74'. Chamber 73' is connecteddirectly with the datum system 58,

etc.

Operation of datum regulator Fuel under charging pressure enters thechamber 72' through the line 56 lifting the valve 75 from its seat, sothat the chamber 73' and datum system 58 is charged with fuel until thefuel pressure on the underside of the diaphragm 71' plus spring pressure74 equals the force of charging pressure acting on the upper side of thediaphragm 71. The pressure of the spring 74' is so calibrated as tomaintain the pressure in the chamber 73' at about 1 to 11/2 pounds gaugepressure less than the charging pressure in the chamber 72. Therestriction 58H in the line 56 functions in the same manner to restrictthe flow into the datum line 58 during operation of the diaphragm 127. l

A structure has been described which will fulfill all of the objects ofthe present invention, but it is contemplated that other modificationswill occur to those skilled in the art which come within the scope ofthe appended claims.

I claim:

1. In an engine charge forming device, in combination, an air passageconnected with the engine, throttle means controlling the flaw of airthrough said passage, a fuel passage to the engine, a fuel pumpsupplying said pasi sage, valve means actuated by the force of fuelpressure t for controlling the ow of fuel through said fuel passage,means for urging said valve in a direction to decrease the fuel supplythrough said passage with a force which is normally constant withrespect to the first force `and independent of the rate `of air flow tothe engine, and means controlled by said throttle and acting directly onsaid means urging said valve in a direction to decrease the fuel supplyfor modifying the force on said valve,

2. In an engine charging device, in combination, an air passageconnected with the engine, throttle means in said air passage, a fuelpump, a fuel passage to the f engine supplied from said pump, a valvefor varying the fuel supply through said passage, means for urging saidValve in a direction to increase the fuel supply with a force whichincreases with an increase in air ow to the engine, means for urgingsaid valve in a direction to decrease the fuel supply to the engine, anda connection between said throttle and one of said means to unbalancethe forces acting on said valve in response to throttle movement wherebyvalve action occurs substantially simultaneously with throttle movementto anticipate changes in air flow to the engine by changing the rate offuel ow to the engine.

3. In an engine charging device, in combination, an air l passageconnected with the engine, throttle means in said air passage, a fuelpump, a fuel passage to the'engineV supplied from said pump, a valve forvarying the fuel flow through said passage, means for urging said valvein a direction to increase the fuel flow with a force which increaseswith an increase in air flow to `the engine, means for urging said valvein a direction to decrease the fuel 1 ow to the engine, anda connectionbetween said throttle gine supplied from said pump, avalve for varyingthe fuel ow through said passage, means for urging said t valve in adirection to increase the fuel ilow with a force which increases with anincrease in air flow to the engine,

`means for urging said valve in a` direction to decrease `iiow thereto.

5. In an engine charge forming device, in combination, an air passageconnected with the engine, throttle means in said air passage, a fuelpump, `a fuel passage to the engine supplied from said pump, a valvefor`varying`the fuel flow through said passage, means for urging saidvalve inta direction to increase the fuel flow with a forcewhichincreases with an increase in air flow to the engine, means for urgingsaid valve in a direction to decrease the fuel flow to the engineincluding a fuel passage connected with said valve and a pressureregulator supplying fuel to said passage at a pressure which is normallyconstant with respect to pump pressure, and a connection between saidthrottle and said pressure regulator acting to unbalance the forces onsaid valve in response to throttle movement whereby valve action occurssubstantially simultaneously with throttle movement to anticipatechanges in air ow to the engine and corresponding changes in lfuelrequirements therefor. i

6. In an engine charging device, in combination, an air passageconnected with the engine, throttle means in said air passage, a fuelpump, a fuel passage to the engine supplied from said pump, a valve forvarying the fuel ilow` through said passage, means for urging said valvein a direction to increase the fuel flow with a force which decreaseswith a decrease in air ow to the engine, means for constantly urgingsaid valve in a direction to decrease the fuel supply to the engine, anda connection between said throttleand one of said means to unbalance theforces acting on said valve in response to throttle closing, wherebyvalve action to decrease fuel ow occurs substantially simultaneouslywith throttle closing to anticipate decreases in air ow to the engineand corresponding decreases in engine fuel requirements.

7. In an engine charge forming device having an air conduit with an airinlet and an air outlet connected with a combustion chamber of theengine, a throtle in said conduit, a fuel chamber, a fuel outlet fromsaid chamber for discharging fuel to the engine combustion chamber, apump supplying fuel under pressure to said chamber, a` regulator havinga movable wall controlling a valve at said outlet, a datum pressuresystem including a bypass extending around said pump, opposed expansiblechambers separated by said movable wall and connected with said datumsystem and said fuel chamber, respectively, whereby said regulatormaintains the fuel at said fuel outlet at a pressure proportional to thecontrol pressure in said datum system, means for temporarily 'varyingthe capacity of said datum system to increase and`decrease the openingof said valve, and a connection between said throttle and said lastnamed means for controlling the action of said valve' in response to`throttle movement.

8. In an engine charge forming device having an air conduit with an airinlet and an air outlet connected with the combustion chamber of anengine, a throttle in said air conduit, an engine fuel charging circuitsupplied with fuel from a pump and discharging from an outlet into thecombustion chamber of the engine, a regulator having a movable Wallcontrolling a valve at said outlet, a datum pressure circuit, opposedexpansible chambers separated by said movable Wall and connected withsaid datum circuit and saidv Acharging circuit, respectively, wherebysaid regulator maintains the fuel in said charging circuit at a pressureproportional to the control pres- .sure in said datum circuit,thecombination therewith of means,` for varying the capacity of saiddatum pressure circuit, and aconnection between said throttle and thelast said means tending to openand close said valve in responseto-throttle movement;

9. Inan engine charge forming device having an air conduit Vwith an-airinlet-and an air outlet connected with a.combustion chamber'of` theengine, a throttle in said conduit, an engine fuel charging circuitsupplied with fuel under pumpv pressure and discharging through anoutlet tothe engine, a datum pressure circuit, and a valve in saidengine charging circuit opened by fluid pressure in said. enginecharging circuit and closed by fuel pressure linsaid datum circuit, thecombination therewith of means for temporarily affecting the pressure inone of said circuits by changing the capacity thereof, and aconnectionfbetween said throttle and the last said means.

10..The combination defined in the preceding claim Wherein=the saidconnection includes a resilient element.

1'1. The combination defined in the preceding claim whereina stop ispositioned to limit movement of said connection, whereby said resilientelementis compressed by further movement of said throttle.

12. .Inra charge forming'system for an internal combustionengine havinga plurality of cylinders, each with an air. intake pipe, a fuel systemcomprising a fuel distributing circuit, means for regulating'the totalfuel flow itsinlet side connectedto said fuel distributing circuit andbeing` adapted to continuously discharge fuel therefrom into itsassociated air intake pipe, valve operating means ifor each of saidvalves, each of said valve operating means having one side responsive tothe pressure of fuel Supplied from said circuit to the inlet side of itsassociated valve for urging the valve in an opening direction, liquidpassage means interconnecting the opposite sides of said valve operatingmeans, pressure regulating means for maintaining a predetermined controlfluid pressure in said liquid passage means acting with equal force oneach of-said valves, a throttle controlled air passage leading to said 1air intake pipes, and throttle operated means for preventing an increasein the controlled fluid pressure by changing the capacity of said liquidpassage means.

13. An engine charge forming device having a system for maintaining theflow of fuel to the engine in one fluid stream proportional to the flowof air to the engine `in a separate fluid stream, said device comprisingmeans'for measuring the ow of air to the engine, a fuel chargingcircuithaving a fuel inlet, a fuel outlet for discharging fuel to the engine, apump supplying fuel under pressure to said inlet, a fuel line normally4pressurized from said pump connecting said inlet and vsaid outlet, apressure regulator having a movable wall vstream proportional to theother, a datum pressure system including a bypass extending around saidpump, opposed expansible chambers separated by said movable lwallandconnected with said datum system and said fuel line, respectively,whereby said regulator maintains the fuelin-said fuel line at a pressureproportional to the pressure in-said datum system, an eXpansible chamberin said datum system forV varying the fuel capacity thereof, a manuallyoperated throttle for controlling the rate of ow of air to the engine,and a connection'between saidthrottle and said expansible chamber forincreasing the capacity of said datum system during throttle opening.

14. Inan engine charge forming device having an air conduit with anairinlet and an air outlet connected with a combustion chamber of theengine, a throttle in said conduit, a fuel chamber, ya fuel outlet fromsaid `chamber for dischargingfuel to the engine combustion chamber,alpump supplying fuel under pressure to said chamber, a regulator havinga movable wall controlling a valve at said outlet, a datum pressuresystem, opposed expansible chambers separated by said movable wall andconnected with said datum system and said fuel chamber, respectively,whereby said regulator maintains the fuel at said fuel outlet at apressure proportional to the control pressure in said datum system,means for establishing a controlled pressure in said datum system, andmeans to maintain the capacity of said datum system constant as saidmovable wall operates to increase valve opening and fuel ow to theengine.

15. In an engine charge forming device having an air conduit with an airinlet and an air outlet connected with the combustion chamber of theengine, a throttle in said conduit, a fuel chamber, a fuel outlet fromsaid chamber for discharging fuel to the engine combustion chamber, apump supplying fuel under pressure to said chamber, a regulator having amovable wall controlling a valve at said outlet, a datum pressuresystem, means for establishing a control pressure in said datum system,opposed expansible chambers separated by said movable wall and connectedwith said datum system and said fuel chamber, respectively, whereby saidregulator maintains the fuel at said fuel outlet at a pressureproportional to the control pressure in said datum system, and means formaintaining the capacity of said datum system substantially constant assaid movable wall operates to close said valve to decrease the fuel flowto the combustion chamber of the engine.

16.' ln an engine charge forming device having an air conduit with an arinlet and an air outlet connected with the combustion chamber of anengine, a throttle in said air conduit, an engine fuel charging circuitsupplied with fuel from a pump and discharging from an outlet into thecombustion chamber of the engine, a regulator having a movable wall forcontrolling a valve at sad outlet, a datum pressure system, means forcharging said datum pressure system with a fluid under controlledpressure, and opposed expansible chambers separated by said mova'blewall and connected with said datum system and said charging circuit,respectively, whereby said regulator maintains the fuel in said chargingcircuit at a pressure proportional to the control pressure in said datumsystem, the combination therewith of means for maintaining the capacityof said datum system substantially constant as said movable walloperates to move said valve to vary the fuel flow from said outlet, anda connection between sad last named means and said throttle.

17. In an engine charging device having an air passage connected'withthe engine, throttle means in said air passage, a fuel inlet, a fueloutlet for discharging fuel to the engine, a pump supplying fuel underpressure to said inlet, a fuel line normally pressurized from said pumpconnecting sad inlet and said outlet, a valve in said outlet, a movablewall controlling said valve, a datum pressure system, opposed expansiblechambers separated by'said movable wall and connected with said datumsystem and said fuel line, respectively, whereby said regulatormaintains the fuel in said fuel line at a pressure proportional to thecontrol pressure in said datum system, means for establishng a controlpressure in said datum system at a fixed differential with respect topump supply pressure, and means in said fuel line for increasing anddecreasing the flow to said outlet valve, the combination therewith ofmeans for varying the capacity of said datum pressure system to produceternporary pressure variations therein, and a connection between saidthrottle and saidlast named means.

18. In an engine charging device having an air passage connected withthe engine, throttle means in said air passage, a fuel inlet, a fuel-outlet discharging fuel to the engine, a pump supplying fuel underpressure to said-inlet, a fuel line normally pressured from said pumpconnecting said inlet and said outlet, a valve controlling said outlet,a movable wall for actuating said valve, a datum pressure system, meansfor controlling the rate of lluid ow into and out of said datum system,opposed expansible chambers separated by said movable wall and connectedwith said datum system and said fuel line, respectively, whereby saidregulator maintains the fuel in said fuel line at a pressureproportional to the,

control pressure in said datum system, means for establishing a controlpressure in said datum system at a tixed dierential with respect to saidpump supply pressure, and means in said fuel line for regulating therate of fuel flow therethrough in accordance with air ow ReferencesCited in the tile of this patent UNITED STATES PATENTS Wineld Nov. 15,1938 Wunsch Feb. 8, 1944

